To determine whether sensitivity could be improved by
performing a microscopic examination prior to the Pastorex®test, a supplementary analysis was conducted. Only samples
with clear positive or negative results for direct microscopy
(defined as above) followed by a Pastorex® test were
included. The samples in this analysis were considered to
be positive only if the results for both Pastorex® and direct
microscopy tests had been positive, and negative if results
for both Pastorex® and direct microscopy tests had been
negative. These combined results were then compared with
the gold standard results as before. Samples with discordant
results for direct microscopy and Pastorex® were excluded
from this analysis (see Figure 1).
Statistical analyses were performed using StataTM 8.2
for Windows (StataCorp, College Station, TX, USA) statistical
software. Calculation of misclassification was performed
using the DAG Stat Excel spreadsheet (Mackinnon, 2000).